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Behshad Y, Pazhang M, Najavand S, Sabzi M. Enhancing Enzyme Stability and Functionality: Covalent Immobilization of Trypsin on Magnetic Gum Arabic Modified Fe 3O 4 Nanoparticles. Appl Biochem Biotechnol 2024; 196:5283-5300. [PMID: 38153653 DOI: 10.1007/s12010-023-04830-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2023] [Indexed: 12/29/2023]
Abstract
This study aimed to fabricate gum Arabic (GA)-coated Fe3O4 nanoparticles bearing numerous active aldehyde groups on their surface, followed by an assessment of their capability as a magnetic support for the covalent immobilization of the trypsin enzyme for the first time. FT-IR, XRD, TGA, and SEM results demonstrated the successful synthesis of GA-coated Fe3O4 nanoparticles, along with the covalent immobilization of the enzyme onto the support. Immobilization enhanced the relative enzymatic activity across a range of aqueous solution pH levels (ranging from 4 to 11) and temperatures (ranging from 20 to 80 °C) without altering the optimum pH and temperature for trypsin activity. Kinetic studies using Michaelis-Menten plots revealed changes in kinetic parameters, including a lower Vmax and higher Km for immobilized trypsin compared to the free enzyme. The immobilization onto magnetic gum Arabic nanoparticles resulted in an improved stability of trypsin in the presence of various solvents, maintaining a stability order comparable to that of the free enzyme due to the stabilizing effect of the support. The reusability results showed that the immobilized enzyme can retain over 93% of its activity for up to 15 cycles.
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Affiliation(s)
- Yasaman Behshad
- Department of Cellular and Molecular Biology, Faculty of Science, Azarbaijan Shahid Madani University, Tabriz, Iran
| | - Mohammad Pazhang
- Department of Cellular and Molecular Biology, Faculty of Science, Azarbaijan Shahid Madani University, Tabriz, Iran.
| | - Saeed Najavand
- Department of Cellular and Molecular Biology, Faculty of Science, Azarbaijan Shahid Madani University, Tabriz, Iran
| | - Mohammad Sabzi
- Department of Mechanical Engineering, North Dakota State University, Fargo, ND, 58102, USA.
- Department of Chemical Engineering, Faculty of Engineering, University of Maragheh, Maragheh, 55181-83111, Iran.
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2
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Reactivity of a Recombinant Esterase from Thermus thermophilus HB27 in Aqueous and Organic Media. Microorganisms 2022; 10:microorganisms10050915. [PMID: 35630360 PMCID: PMC9143606 DOI: 10.3390/microorganisms10050915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/19/2022] [Accepted: 04/22/2022] [Indexed: 11/16/2022] Open
Abstract
The thermoalkalophilic membrane-associated esterase E34Tt from Thermus thermophilus HB27 was cloned and expressed in Kluyveromyces lactis (KLEST-3S esterase). The recombinant enzyme was tested as a biocatalyst in aqueous and organic media. It displayed a high thermal stability and was active in the presence of 10% (v/v) organic solvents and 1% (w/v) detergents. KLEST-3S hydrolysed triglycerides of various acyl chains, which is a rare characteristic among carboxylic ester hydrolases from extreme thermophiles, with maximum activity on tributyrin. It also displayed interfacial activation towards triacetin. KLEST-3S was also tested as a biocatalyst in organic media. The esterase provided high yields for the acetylation of alcohols. In addition, KLEST-3S catalyzed the stereoselective hydrolysis of (R,S)-ibuprofen methyl ester (87% ee). Our results indicate that KLEST-3S may be a robust and efficient biocatalyst for application in industrial bioconversions.
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3
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Sharma A, Thatai KS, Kuthiala T, Singh G, Arya SK. Employment of polysaccharides in enzyme immobilization. REACT FUNCT POLYM 2021. [DOI: 10.1016/j.reactfunctpolym.2021.105005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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4
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Chitosan derivative functionalized carbon nanotubes as carriers for enzyme immobilization to improve synthetic efficiency of ethyl caproate. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111897] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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5
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Aslan Y, Sharif YM, Şahin Ö. Covalent immobilization of Aspergillus niger amyloglucosidase (ANAG) with ethylenediamine-functionalized and glutaraldehyde-activated active carbon (EFGAAC) obtained from sesame seed shell. Int J Biol Macromol 2020; 142:222-231. [DOI: 10.1016/j.ijbiomac.2019.09.226] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 09/22/2019] [Accepted: 09/24/2019] [Indexed: 01/06/2023]
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6
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Onoja E, Chandren S, Razak FIA, Wahab RA. Extraction of nanosilica from oil palm leaves and its application as support for lipase immobilization. J Biotechnol 2018; 283:81-96. [DOI: 10.1016/j.jbiotec.2018.07.036] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 07/14/2018] [Accepted: 07/27/2018] [Indexed: 01/03/2023]
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7
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Facile modulation of enantioselectivity of thermophilic Geobacillus zalihae lipase by regulating hydrophobicity of its Q114 oxyanion. Enzyme Microb Technol 2016; 93-94:174-181. [DOI: 10.1016/j.enzmictec.2016.08.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 08/20/2016] [Accepted: 08/30/2016] [Indexed: 01/04/2023]
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8
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Enzymatic Hydrolytic Resolution of Racemic Ibuprofen Ethyl Ester Using an Ionic Liquid as Cosolvent. Molecules 2016; 21:molecules21070905. [PMID: 27420042 PMCID: PMC6274346 DOI: 10.3390/molecules21070905] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 06/27/2016] [Accepted: 07/07/2016] [Indexed: 11/17/2022] Open
Abstract
The aim of this study was to develop an ionic liquid (IL) system for the enzymatic resolution of racemic ibuprofen ethyl ester to produce (S)-ibuprofen. Nineteen ILs were selected for use in buffer systems to investigate the effects of ILs as cosolvents for the production of (S)-ibuprofen using thermostable esterase (EST10) from Thermotoga maritima. Analysis of the catalytic efficiency and conformation of EST10 showed that [OmPy][BF₄] was the best medium for the EST10-catalyzed production of (S)-ibuprofen. The maximum degree of conversion degree (47.4%), enantiomeric excess of (S)-ibuprofen (96.6%) and enantiomeric ratio of EST10 (177.0) were achieved with an EST10 concentration of 15 mg/mL, racemic ibuprofen ethyl ester concentration of 150 mM, at 75 °C , with a reaction time of 10 h. The reaction time needed to achieve the highest yield of (S)-ibuprofen was decreased from 24 h to 10 h. These results are relevant to the proposed application of ILs as solvents for the EST10-catalyzed production of (S)-ibuprofen.
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9
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An B, Fan H, Wu Z, Zheng L, Wang L, Wang Z, Chen G. Ultrasound-Assisted Enantioselective Esterification of Ibuprofen Catalyzed by a Flower-Like Nanobioreactor. Molecules 2016; 21:molecules21050565. [PMID: 27136511 PMCID: PMC6273997 DOI: 10.3390/molecules21050565] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 04/22/2016] [Accepted: 04/25/2016] [Indexed: 11/16/2022] Open
Abstract
A flower-like nanobioreactor was prepared for resolution of ibuprofen in organic solvents. Ultrasound irradiation has been used to improve the enzyme performance of APE1547 (a thermophilic esterase from the archaeon Aeropyrum pernix K1) in the enantioselective esterification. Under optimum reaction conditions (ultrasound power, 225 W; temperature, 45 °C; water activity, 0.21), the immobilized APE1547 showed an excellent catalytic performance (enzyme activity, 13.26 μmol/h/mg; E value, 147.1). After ten repeated reaction batches, the nanobioreactor retained almost 100% of its initial enzyme activity and enantioselectivity. These results indicated that the combination of the immobilization method and ultrasound irradiation can enhance the enzyme performance dramatically.
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Affiliation(s)
- Baiyi An
- College of Horticulture, Jilin Agricultural University, Changchun 130118, China.
| | - Hailin Fan
- College of Resources and Environment, Jilin Agricultural University, Changchun 130118, China.
| | - Zhuofu Wu
- College of Life Science, Jilin Agricultural University, Changchun 130118, China.
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China.
| | - Lu Zheng
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China.
| | - Lei Wang
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China.
| | - Zhi Wang
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China.
| | - Guang Chen
- College of Life Science, Jilin Agricultural University, Changchun 130118, China.
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10
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Ravelo M, Esteban J, Ladero M, García-Ochoa F. Enzymatic synthesis of ibuprofen monoglycerides catalyzed by free Candida antarctica lipase B in a toluene–glycerol biphasic medium. RSC Adv 2016. [DOI: 10.1039/c6ra15480h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Reactive distillation in the presence of toluene permits the intensification of ibuprofen monoglyceride synthesis by means of aCandida antarcticaindustrial solution, attaining total conversion.
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Affiliation(s)
- Marianela Ravelo
- Department of Chemical Engineering
- Complutense University of Madrid
- Madrid
- Spain
| | - Jesús Esteban
- Department of Chemical Engineering
- Complutense University of Madrid
- Madrid
- Spain
| | - Miguel Ladero
- Department of Chemical Engineering
- Complutense University of Madrid
- Madrid
- Spain
| | - Félix García-Ochoa
- Department of Chemical Engineering
- Complutense University of Madrid
- Madrid
- Spain
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11
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Development of a catalytically stable and efficient lipase through an increase in hydrophobicity of the oxyanion residue. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.molcatb.2015.10.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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12
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Che Marzuki NH, Mahat NA, Huyop F, Buang NA, Wahab RA. Candida rugosa Lipase Immobilized onto Acid-Functionalized Multi-walled Carbon Nanotubes for Sustainable Production of Methyl Oleate. Appl Biochem Biotechnol 2015; 177:967-84. [DOI: 10.1007/s12010-015-1791-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Accepted: 07/30/2015] [Indexed: 10/23/2022]
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13
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José C, Toledo MV, Briand LE. Enzymatic kinetic resolution of racemic ibuprofen: past, present and future. Crit Rev Biotechnol 2015; 36:891-903. [DOI: 10.3109/07388551.2015.1057551] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Carla José
- Centro de Investigación y Desarrollo en Ciencias Aplicadas – Dr. Jorge J. Ronco (CINDECA), Universidad Nacional de La Plata, CONICET, CCT La Plata, Calle 47 No 257, B1900AJK La Plata, Buenos Aires, Argentina
| | - María Victoria Toledo
- Centro de Investigación y Desarrollo en Ciencias Aplicadas – Dr. Jorge J. Ronco (CINDECA), Universidad Nacional de La Plata, CONICET, CCT La Plata, Calle 47 No 257, B1900AJK La Plata, Buenos Aires, Argentina
| | - Laura E. Briand
- Centro de Investigación y Desarrollo en Ciencias Aplicadas – Dr. Jorge J. Ronco (CINDECA), Universidad Nacional de La Plata, CONICET, CCT La Plata, Calle 47 No 257, B1900AJK La Plata, Buenos Aires, Argentina
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14
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Jiang L, Xie X, Yue H, Wu Z, Wang H, Yang F, Wang L, Wang Z. Highly efficient and regioselective acylation of arbutin catalyzed by lipase from Candida sp. Process Biochem 2015. [DOI: 10.1016/j.procbio.2015.02.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Mohamad NR, Buang NA, Mahat NA, Lok YY, Huyop F, Aboul-Enein HY, Abdul Wahab R. A facile enzymatic synthesis of geranyl propionate by physically adsorbed Candida rugosa lipase onto multi-walled carbon nanotubes. Enzyme Microb Technol 2015; 72:49-55. [DOI: 10.1016/j.enzmictec.2015.02.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 02/17/2015] [Accepted: 02/25/2015] [Indexed: 10/23/2022]
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16
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Liu W, Hu Y, Zhang Y, Ma Y, Huang H. Enzymatic desymmetrization of 3-(4-fluorophenyl)glutaric anhydride through enantioselective alcoholysis in organic solvents. BIOTECHNOL BIOPROC E 2014. [DOI: 10.1007/s12257-014-0110-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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17
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López G, Chow J, Bongen P, Lauinger B, Pietruszka J, Streit WR, Baena S. A novel thermoalkalostable esterase from Acidicaldus sp. strain USBA-GBX-499 with enantioselectivity isolated from an acidic hot springs of Colombian Andes. Appl Microbiol Biotechnol 2014; 98:8603-16. [PMID: 24818691 DOI: 10.1007/s00253-014-5775-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 04/09/2014] [Accepted: 04/12/2014] [Indexed: 12/28/2022]
Abstract
Several thermo- and mesoacidophilic bacterial strains that revealed high lipolytic activity were isolated from water samples derived from acidic hot springs in Los Nevados National Natural Park (Colombia). A novel lipolytic enzyme named 499EST was obtained from the thermoacidophilic alpha-Proteobacterium Acidicaldus USBA-GBX-499. The gene estA encoded a 313-amino-acid protein named 499EST. The deduced amino acid sequence showed the highest identity (58 %) with a putative α/β hydrolase from Acidiphilium sp. (ZP_08632277.1). Sequence alignments and phylogenetic analysis indicated that 499EST is a new member of the bacterial esterase/lipase family IV. The esterase reveals its optimum catalytic activity at 55 °C and pH 9.0. Kinetic studies showed that 499EST preferentially hydrolyzed middle-length acyl chains (C6-C8), especially p-nitrophenyl (p-NP) caproate (C6). Its thermostability and activity were strongly enhanced by adding 6 mM FeCl3. High stability in the presence of water-miscible solvents such as dimethyl sulfoxide and glycerol was observed. This enzyme also exhibits stability under harsh environmental conditions and enantioselectivity towards naproxen and ibuprofen esters, yielding the medically relevant (S)-enantiomers. In conclusion, according to our knowledge, 499EST is the first thermoalkalostable esterase derived from a Gram-negative thermoacidophilic bacterium.
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Affiliation(s)
- Gina López
- Unidad de Saneamiento y Biotecnología Ambiental, Departamento de Biología, Pontificia Universidad Javeriana, POB 56710, Bogotá, DC, Colombia
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18
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Zhao D, Yue H, Chen G, Jiang L, Zhang H, Wang Z, Liu G. Enzymatic resolution of ibuprofen in an organic solvent under ultrasound irradiation. Biotechnol Appl Biochem 2014; 61:655-9. [PMID: 24698427 DOI: 10.1002/bab.1229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 03/25/2014] [Indexed: 11/08/2022]
Abstract
Ultrasound has been successfully adopted to improve the biocatalytic properties of APE1547 (a novel esterase from the archaeon Aeropyrum pernix K1) in the resolution of ibuprofen. After optimizing the conditions (ultrasound power, 200 W; temperature, 35 °C), the best biocatalytic performance of APE1547 (enzyme activity, 5.39 µmol/H/mg; E value, 130.8) was obtained. Compared with the conventional reaction in an orbital shaker, the enzyme activity was significantly enhanced about 90-fold, and the enantioselectivity was enhanced about fourfold after an ultrasound. The results of scanning electron microscopy clearly indicated that the activation effect of ultrasound on APE1547 originated mainly in the morphological change of the enzyme powder. Both lower particle size and conformational change of APE1547 under ultrasound might be helpful to enhance the enantioselectivity. In addition, APE1547 kept its best performance under the low-power ultrasound for at least five reaction cycles.
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Affiliation(s)
- Dantong Zhao
- Liaoning Key Laboratory of Urban Integrated Pest Management and Ecological Security, Shenyang University, Shenyang, People's Republic of China; Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, Jilin University, Changchun, People's Republic of China
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19
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Shang W, Zhang X, Yang X, Zhang S. High pressure CO2-controlled reactors: enzymatic chiral resolution in emulsions. RSC Adv 2014. [DOI: 10.1039/c4ra02131b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Chiral separation of ibuprofen catalyzed by enzyme conducted in CO2-based micelle makes the reaction more effective and greener.
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Affiliation(s)
- Wenting Shang
- Department of Chemistry
- Renmin University of China
- Beijing, P.R. China
| | - Xiaogang Zhang
- Department of Chemistry
- Renmin University of China
- Beijing, P.R. China
| | - Xiaoxi Yang
- Department of Chemistry
- Renmin University of China
- Beijing, P.R. China
| | - Shujuan Zhang
- Department of Chemistry
- Renmin University of China
- Beijing, P.R. China
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20
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Cloning, expression and characterization of a new enantioselective esterase from a marine bacterium Pelagibacterium halotolerans B2T. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcatb.2013.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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21
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Enantioselective esterification of ibuprofen under microwave irradiation. Molecules 2013; 18:5472-81. [PMID: 23669631 PMCID: PMC6270588 DOI: 10.3390/molecules18055472] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/03/2013] [Accepted: 05/06/2013] [Indexed: 11/27/2022] Open
Abstract
Enantioselective esterification of ibuprofen has been successfully carried out in an organic solvent catalyzed by recombinant APE 1547 (a thermophilic esterase from the archaeon Aeropyrum pernix K1). Here we used microwave irradiation (MW) as the mode of heating to improve the enzyme performance. Under the optimum conditions, the enzyme activity of APE 1547 was 4.16 μmol/mg/h and the enantioselectivity (E value) was 52.9. Compared with conventional heating, the enzyme activity and the enantioselectivity were increased about 21.9-fold and 1.4-fold, respectively. The results also indicated that APE 1547 can maintain 95% of its activity even after being used five times, suggesting that the enzyme is stable under low power MW conditions.
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Li X, Liu T, Xu L, Gui X, Su F, Yan Y. Resolution of racemic ketoprofen in organic solvents by lipase from Burkholderia cepacia G63. BIOTECHNOL BIOPROC E 2013. [DOI: 10.1007/s12257-012-0279-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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23
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Abstract
Enzyme immobilization has been investigated to improve lipase properties over the past few decades. Different methods and various carriers have been employed to immobilize enzyme. However, the application of enzymatic technology in large scale is rarely seen during the industrial process. The main obstacles are a high cost of the immobilization and the poor performance of immobilized lipase. This review focuses on the current status of enzyme immobilization, which aims to summarize the latest research on the parameters affecting the performance of immobilized enzyme. Particularly, the effect of immobilization methods, immobilization carriers, and enzyme loading has been discussed.
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Combination of oxyanion Gln114 mutation and medium engineering to influence the enantioselectivity of thermophilic lipase from Geobacillus zalihae. Int J Mol Sci 2012; 13:11666-11680. [PMID: 23109876 PMCID: PMC3472768 DOI: 10.3390/ijms130911666] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 08/10/2012] [Accepted: 08/20/2012] [Indexed: 11/17/2022] Open
Abstract
The substitution of the oxyanion Q114 with Met and Leu was carried out to investigate the role of Q114 in imparting enantioselectivity on T1 lipase. The mutation improved enantioselectivity in Q114M over the wild-type, while enantioselectivity in Q114L was reduced. The enantioselectivity of the thermophilic lipases, T1, Q114L and Q114M correlated better with log p as compared to the dielectric constant and dipole moment of the solvents. Enzyme activity was good in solvents with log p < 3.5, with the exception of hexane which deviated substantially. Isooctane was found to be the best solvent for the esterification of (R,S)-ibuprofen with oleyl alcohol for lipases Q114M and Q114L, to afford E values of 53.7 and 12.2, respectively. Selectivity of T1 was highest in tetradecane with E value 49.2. Solvents with low log p reduced overall lipase activity and dimethyl sulfoxide (DMSO) completely inhibited the lipases. Ester conversions, however, were still low. Molecular sieves employed as desiccant were found to adversely affect catalysis in the lipase variants, particularly in Q114M. The higher desiccant loading also increased viscosity in the reaction and further reduced the efficiency of the lipase-catalyzed esterifications.
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